Fresnel diffraction

LEDs and LED microscope lighting have come a long way since they were first developed for microscopy in 2006. The wealth of benefits compared to traditional microscope lighting such as mercury and metal halide lamps are driving more and more scientists towards this efficient, highly controllable technology.

The use of lenses in lighthouses began in England in the 18th century, and was adopted in the United States by 1810. These early lenses were thick, excessively heavy, and of poor quality glass. Therefore, they were not very effective and prone to losing the light through the thick glass. In 1811, the French Commission on Lighthouses established a committee to investigate improvements in lighthouse illumination. Among the committee members was Augustin Fresnel, who in 1822 completed the design of his flashing lens using thin bull’s eye shaped panels, which refracted the light both horizontally and vertically, producing a much stronger beam of light.

Fresnel Light

Since 2006 when our team of four launched the first commercially available LED illumination system, we have led the way in transforming light source technology. We cover fluorescence microscopy and transmitted light applications, backed by our technical know-how and unique blend of optical engineering and life science expertise.

Fresnel equations

But if things do occasionally go wrong, we are there to offer local support through our global network of resellers and Global Sales Team, which means there is always an expert available to help.

LED illumination systems are cleaner, have a long lifetime and use less power. Our pE-300 Series is also ACT label certified and is a natural choice for labs who want to play their part in helping the environment.

LED Microscope Lighting Performance: Being solid-state, LEDs are much more stable over time, leading to a robust level of irradiance and highly repeatable experiments.

Fresnel company

CoolLED is a fast-growing organisation based in the UK. We draw on the latest technology to design and manufacture a vast range of cutting-edge LED microscope lighting solutions for researchers and clinicians.

Whether using fluorescence or transmitted light, or a compound or stereomicroscope, high-quality science begins with high-quality microscope components – including the light source.

Fresnel lens

LED Microscope Lighting Control: Unlike mercury and metal halide lamps which require mechanical shutters, electronic control of LEDs is simple and fast. The ability to switch them on and off with precise microsecond timing is perfect for capturing high-speed events, and electronic modulation of irradiance means no more neutral density filters.

LED Microscope Lighting Safety and the Environment: There is no denying that mercury is hazardous, unlike LEDs. LEDs are also more energy efficient, emit much less heat and are in many ways better for the environment.

CoolLED LED lighting systems are renowned for being robust and reliable. In fact, we recently heard from a customer who purchased one of our first ever products on the market, and who told us: “Our precisExcite is working in a fantastic manner for over 10 years. It has already contributed to more than 10 publications from the lab and will continue to do so.” – Charles Harata, Associate Professor, Department of Molecular Physiology & Biophysics at the University of Iowa

Most Fresnel lenses look like a beehive or barrel; most contain from two to twenty-four different panels. A clock type mechanism, which had to be wound by hand every few hours before automation, was used to make the revolving lenses rotate around the lamp itself to produce the flash. The movement of the lens is timed precisely so the panel will pass by when a flash is due.

Nearly all lighthouses in National Park units originally had a Fresnel lens, though many of them have been removed and/or replaced with more modern lighting mechanisms. However, the lenses’ beauty and their pivotal place in lighthouse history has ensured their preservation in many instances. Some are in museums associated with the historic lighthouse itself; others are in museums away from the lighthouse. And of course, there are many, many more Fresnel lenses in American lighthouses that are not part of National Parks. The United States Lighthouse Society maintains a large amount of information about Fresnel lens history and technology, as well as lists of current and operational Fresnel lenses in the United States.

Fresnel lenses came in several sizes, or orders, from the largest, the Hyper-Radial, to the smallest, the eighth order. Not all orders were used in the United States. Large first order lenses, such as those still in place at the Fowey Rocks lighthouse in Biscayne National Park or the Bodie Island lighthouse in Cape Hatteras National Seashore, were usually used on major seacoasts, with a more powerful beam that shines up to twenty-one miles out to sea. Fifth or sixth order lights, the smallest used in the United States, were used in smaller bodies of water, such as bays or rivers. The Jones Point lighthouse on the Potomac River in Alexandria, Virginia, used a fifth order lens for the comparatively smaller distances it had to cover, but it was nonetheless essential to the hundreds of merchant, passenger, fishing, and naval vessels that traveled the waters around Washington, DC daily.

LED Microscope Lighting Cost: In addition to saving on components, the longer lifetime of LEDs is cheaper in the long-term. You also avoid specialist disposal charges due to the high-pressure lamp and mercury content. Take a look at this study by Green Light Laboratories.

For manufacturers who wish to gain a competitive advantage through bright, stable and controllable illumination, CoolLED’s world-renowned LED technology is available in customised configurations.

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Fresnel pronunciation

We have a record of >99% on-time delivery in full against acknowledged delivery dates and we pride ourselves on friendly and expert advice whenever it is needed. You will also be covered by our market-leading warranty, which includes three years as standard for all products and a 12 month in-for-out swap if we cannot fix an issue.

A range of LED lighting products are available with a variety of LEDs and different levels of control. Single wavelength models are ideal for screening applications, and simple white light options are the perfect replacement for a mercury/metal halide lamp. For controllable, everyday fluorescence, the pE-300 Series offers three wavelengths covering all the common fluorophores. Our range extends to the high-end pE-4000 LED microscope lighting solution which offers 16 wavelengths, spanning 365 nm-770 nm. This can excite in the UV region and right through to fluorophores at the IR end of the spectrum (which is ideal for imaging thick samples while protecting against phototoxicity). This even opens up the development of new fluorophores which no longer depend on the emission spectrum of a mercury/metal halide lamp.

Fresnel Aputure

Did you know that LED illumination systems help laboratories reduce their carbon footprint, protecting laboratory staff along the way?

The Fresnel lens (pronounced "Frey Nel"), as it came to be known, represented a monumental step forward in lighthouse lighting technology, and therefore also in maritime safety. In a Fresnel lens, hundreds of pieces of specially cut glass surround a lamp bulb. This design intensifies the glow from the light, focusing rays of light that would normally scatter into a single, intense beam of light, which shines out in a specific direction. The lens could produce an unlimited number of flashing combinations and intensified the light so it could be seen at greater distances, allowing mariners a greater deal of safety in their navigations near shore.

We also understand that something out of the ordinary is sometimes required, and manufacturers wishing to gain a competitive advantage can now access our world-renowned LED technology in customised configurations at www.OEMIllumination.com.

Fresnel lenses may be fixed, showing a steady light all around the horizon, or revolving, producing a flash. The number of flashes per minute is determined by the number of flash panels and the speed at which the lens revolves. A unique flash pattern for each light is produced by varying the amount of light and dark periods. For example, a light can send out a flash regularly every five seconds. Alternatively, it might have a ten second period of darkness and a three second period of brightness, or any number of other combinations. The individual flashing pattern of each light is called its characteristic. Mariners consult a light list or a maritime chart that told what light flashes that particular characteristic, and what color the light is. This allowed them to determine their position at sea in relation to the land.

If you’re not sure whether a CoolLED Illumination System is right for you, we can provide a free loan unit for testing, with no obligation to purchase. Please contact us at [email protected] for more information.

Fresnel effect

Our systems are dedicated to enhancing data generation and interpretation for researchers and clinicians through generating bright, high-contrast images. Unlike standard LEDs, our unique active cooling technology and expert LED assembly enables irradiance levels up to five times greater than other LED microscope lighting options. Thermal management holds the LEDs at a constant temperature, allowing us to drive them more powerfully. This increases irradiance, stability, reliability and lifetime, while offering the lowest energy consumption on the market. CoolLED is also the only company to provide direct fit products as an alternative to light delivery with a liquid light guide. This is the most efficient means of light delivery to a microscope and is our most popular type of LED microscope lighting solution. It harnesses more power, while also reducing total cost of ownership thanks to fewer consumables.

LED lighting systems are available for fluorescence microscopy and transmitted light applications. Take a look at our product range to discover which system is best suited to your requirements.

At CoolLED we are committed to giving our customers outstanding service right from the start and throughout the lifetime of the product. Please get in touch if you have any questions or would like a quote. You can also browse our site for technical resources and general support.

Toxic mercury-based microscope illuminators are bad news for the environment, draw a lot of power and have a short lifetime.

LED Microscope Lighting Convenience: LEDs are long-lived and don’t require tricky alignment. Once you switch them on they are ready to be used.